<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        *{padding: 0;margin: 0;}
        .nav{
            width: 100%;
            height: 64px;
            color: white;
            background: rgb(63, 43, 21);
            position: absolute;
        }
        .nav1{
            width: 100%;
            height: 64px;
            color: white;
            background: rgba(63, 43, 21,0.6);
            position: absolute;
        }
    </style>
</head>
<body>
<div class="nav">
    呀呼 jiao...jiao
</div>
<div class="nav1">
</div>
</body>
</html>